In a display device formed by a current-driven light-emitting element existing in the prior art, the problem of transistor threshold voltage is one of the most primary problems affecting display performance. Specifically, a driving current of a light-emitting element is supplied by a transistor under the control of a corresponding data voltage. Once threshold voltages of transistors of different pixels have a difference of more than 0.1 V, the driving current under the same data voltage will show significant deviation, which will cause a difference in luminance of light-emitting elements of different pixels, and result in an hourglass phenomenon on a display image.
In order to compensate for the threshold voltage of each transistor, a circuit in the prior art typically first stores threshold voltages of transistors that drive pixels in a storage capacitor prior to displaying light-emission in the manner of adding transistors and adding signal lines in a row direction, so as to counteract the influence caused by threshold voltages on the driving current at the time of light emission. However, as the market's demands for high resolution increase, the number of transistors and the number of signal lines in the row direction required for the threshold voltage compensation circuit of such type have become a requirement that is impossible to meet. Therefore, how to reduce the number of transistors within a pixel area and the number of signal lines in the row direction while realizing the function of threshold voltage compensation has become an urgent technical problem that needs to be solved in meeting the needs of high-resolution of display products in the art.